Shin Getter Robo!! Ibun - Try To Remember

Written by Yasuhiro Imagawa and illustrated by Hisashi Matsumoto. The manga was serialized in Kodansha's Super Robot Battle Tribute. While the characters, terms, and the worldview have some parts in common with the OVA, the stories presented in the manga are different from that of the OVA. In addition, characters from Go Nagai's manga Gakuen Taikutsu Otoko also appear.

(Source: Wikipedia)